Hypervisors can be updated several times a year to provide new features and to address bugs, compatibility issues, and emergent security issues. To effect the update, a hypervisor can be used to update its own disk image; rebooting then results in the update. During this procedure, applications hosted by the hypervisor may have to be checkpointed (e.g., suspended and copied to disk) and restarted; the resulting interruption of the applications may be at best undesirable and, in many cases, may be unacceptable. The need to restart applications can be avoided by migrating them (and their respective virtual machines and/or containers) to other hardware-plus-hypervisor systems; however, the resulting network bandwidth consumption and inevitable performance hits can be unacceptable. So, minimizing interruptions and performance penalties associated with hypervisor updates continues to be an important objective.